rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P10829/1:b..l (detected by 0, t=10504 jiffies, g=53317, q=741 ncpus=2) task:syz.0.1979 state:R running task stack:25712 pid:10829 ppid:4838 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6874 irqentry_exit+0x63/0x70 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x60 kernel/kcov.c:219 Code: 8b 15 a5 fa 7f 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 1c 16 00 00 00 74 2c 8b 91 f8 15 00 00 83 fa 02 75 21 <48> 8b 91 00 16 00 00 48 8b 32 48 8d 7e 01 8b 89 fc 15 00 00 48 39 RSP: 0018:ffffc9000d057ab8 EFLAGS: 00000246 RAX: ffffffff886afdff RBX: 0000000000000001 RCX: ffff88802e739dc0 RDX: 0000000000000002 RSI: 0000000000000001 RDI: 0000000000000008 RBP: ffffc9000d057c50 R08: ffffffff8fa0c048 R09: ffffffff8fa0c058 R10: ffffffff8fa0c050 R11: ffffffff8fa0c043 R12: 00000067c63a3e41 R13: 0000000000000000 R14: dffffc0000000000 R15: 0000607f46e34850 __bpf_prog_run include/linux/filter.h:600 [inline] bpf_prog_run include/linux/filter.h:614 [inline] bpf_test_run+0x51f/0x830 net/bpf/test_run.c:402 bpf_prog_test_run_skb+0xaa6/0x12a0 net/bpf/test_run.c:1191 bpf_prog_test_run+0x31e/0x390 kernel/bpf/syscall.c:3695 __sys_bpf+0x62b/0x780 kernel/bpf/syscall.c:5049 __do_sys_bpf kernel/bpf/syscall.c:5135 [inline] __se_sys_bpf kernel/bpf/syscall.c:5133 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5133 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fd42419c799 RSP: 002b:00007fd425038028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fd424415fa0 RCX: 00007fd42419c799 RDX: 0000000000000050 RSI: 0000200000000100 RDI: 000000000000000a RBP: 00007fd424232c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd424416038 R14: 00007fd424415fa0 R15: 00007ffc8e8634c8 rcu: rcu_preempt kthread timer wakeup didn't happen for 10481 jiffies! g53317 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=28845 rcu: rcu_preempt kthread starved for 10482 jiffies! g53317 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:I stack:27736 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x303/0x1340 kernel/rcu/tree.c:1706 rcu_gp_kthread+0x99/0x3b0 kernel/rcu/tree.c:1905 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 10832 Comm: syz.2.1978 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:check_preemption_disabled+0x0/0x110 lib/smp_processor_id.c:13 Code: c7 a0 9d bc 8c 4c 89 f6 e8 8d 34 0b fa e9 6e ff ff ff 00 00 cc cc 00 00 cc cc 48 c7 c7 c0 0c df 8a 48 c7 c6 00 0d df 8a eb 00 <55> 41 57 41 56 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 RSP: 0018:ffffc900001e09b8 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 5900acff18175900 RDX: 0000000000000000 RSI: ffffffff8a8c1d80 RDI: ffffffff8adf0d20 RBP: ffffc900001e0ac8 R08: ffffffff8e1fdeef R09: 1ffffffff1c3fbdd R10: dffffc0000000000 R11: fffffbfff1c3fbde R12: 0000000000000001 R13: 1ffff9200003c144 R14: 0000000000000046 R15: dffffc0000000000 FS: 00007f8c1aa546c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fcc5d94da08 CR3: 00000000448e2000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: lockdep_recursion_inc kernel/locking/lockdep.c:462 [inline] lock_acquire+0x181/0x4a0 kernel/locking/lockdep.c:5661 rcu_lock_acquire include/linux/rcupdate.h:350 [inline] rcu_read_lock include/linux/rcupdate.h:791 [inline] trace_call_bpf+0xe0/0x6b0 kernel/trace/bpf_trace.c:134 perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:10027 perf_trace_preemptirq_template+0x268/0x320 include/trace/events/preemptirq.h:14 trace_irq_enable_rcuidle+0xd3/0x140 include/trace/events/preemptirq.h:40 trace_hardirqs_on+0x24/0x40 kernel/trace/trace_preemptirq.c:44 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:728 RIP: 0010:variable_ffs arch/x86/include/asm/bitops.h:319 [inline] RIP: 0010:handle_softirqs+0x1c8/0x930 kernel/softirq.c:584 Code: 89 7c 24 44 0f b7 db 48 c7 c7 80 06 8b 8a e8 0f 70 de 08 65 66 c7 05 a5 35 b4 7e 00 00 e8 c0 72 39 00 fb 49 c7 c6 c0 a0 80 8c <89> 5c 24 4c b8 ff ff ff ff 0f bc 44 24 4c 41 89 c5 41 ff c5 0f 84 RSP: 0018:ffffc900001e0e00 EFLAGS: 00000286 RAX: 5900acff18175900 RBX: 0000000000000200 RCX: 5900acff18175900 RDX: dffffc0000000000 RSI: ffffffff8a8c10a0 RDI: ffffffff8adf0d20 RBP: ffffc900001e0f30 R08: ffff8880b8f3580b R09: 1ffff110171e6b01 R10: dffffc0000000000 R11: ffffed10171e6b02 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff8c80a0c0 R15: 000000000000000a __do_softirq kernel/softirq.c:630 [inline] invoke_softirq kernel/softirq.c:470 [inline] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:__rcu_read_unlock+0x51/0xd0 kernel/rcu/tree_plugin.h:425 Code: ec 03 43 0f b6 04 3c 84 c0 75 48 ff 0b 75 1d 4c 8d b7 40 04 00 00 4c 89 f0 48 c1 e8 03 42 0f b6 04 38 84 c0 75 5f 41 83 3e 00 <75> 20 43 0f b6 04 3c 84 c0 75 3a 8b 03 3d 00 00 00 40 73 0a 5b 41 RSP: 0018:ffffc9000d967298 EFLAGS: 00000202 RAX: 0000000000000000 RBX: ffff88805397bfbc RCX: 0000000000080000 RDX: ffffc90012870000 RSI: 000000000000fe11 RDI: ffff88805397bb80 RBP: dffffc0000000000 R08: ffff88801b5dd67f R09: 1ffff110036bbacf R10: dffffc0000000000 R11: ffffed10036bbad0 R12: 1ffff1100a72f7f7 R13: 0000000000000000 R14: ffff88805397bfc0 R15: dffffc0000000000 rcu_read_unlock include/linux/rcupdate.h:823 [inline] page_ext_put+0x91/0xb0 mm/page_ext.c:182 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1486 [inline] free_pcp_prepare mm/page_alloc.c:1536 [inline] free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3413 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3508 __vunmap+0x856/0xa00 mm/vmalloc.c:2726 bpf_check+0x9ec7/0x10db0 kernel/bpf/verifier.c:15694 bpf_prog_load+0x101a/0x1560 kernel/bpf/syscall.c:2651 __sys_bpf+0x5b8/0x780 kernel/bpf/syscall.c:5031 __do_sys_bpf kernel/bpf/syscall.c:5135 [inline] __se_sys_bpf kernel/bpf/syscall.c:5133 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5133 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f8c19b9c799 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f8c1aa54028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f8c19e16090 RCX: 00007f8c19b9c799 RDX: 0000000000000080 RSI: 0000200000000100 RDI: 0000000000000005 RBP: 00007f8c19c32c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8c19e16128 R14: 00007f8c19e16090 R15: 00007ffcdc4a9a08